<b>Background:</b> Predictive biomarkers for immunotherapy in lung cancer are intensively investigated; however, correlations between PD-L1/PD-1 expressions and clinical features or histopathological tumor characteristics determined on hematoxylin and eosin stained sections have not extensively been studied.
Lung cancer cell line demethylation resulting from 5-Aza-2'-deoxycytidine treatment was associated with both NY-ESO-1 and PD-L1 re-expression <i>in vitro</i> but not increased chemosensitivity.
Lung cancer was associated with good overall survival and disease-free survival (HR 0.639; 95% CI 0.491, 0.831; and HR 0.693; 95% CI 0.538, 0.891, respectively) for PD-1-positive tumor-infiltrating lymphocytes, and colorectal cancer showed favorable disease-free survival (HR 0.471; 95% CI 0.308, 0.722) for PD-L1-positive tumor-infiltrating lymphocytes.
PD-L1 expression was examined in 220 non-small cell lung cancer specimens that were consecutively resected at our hospital after validating the E1L3N antibody immunohistochemical assay by comparing IHC and RT-PCR data for lung cancer cell lines.
PD-L1 expressing CETCs were detected in 94.5% of breast, 100% of prostate, 95.4% of colorectal and 82% of lung cancer patients whereas only 75% of breast cancer patients had PD-L2 positive CETCs.
PD-L1 expression was evaluated using the SP142 assay in 37 NSCLC patients with paired primary lung cancer and surgically resected metastases at recurrence.
PD-L1 expression was evaluated by immunohistochemistry with the antibody clone SP142 in 263 patients with surgically resected primary small-sized lung cancer.
PD-L1 IHC assays have been clinically validated only on formalin-fixed paraffin-embedded tissue; however, lung cancer is frequently diagnosed on cytology.